Ho Chi Minh’s thought on international solidarity is an important content of his thoughts about Vietnamese revolutionary path. During the struggle for national liberation and national construction, Cambodia, Vietnam and Laos have applied innovatively Ho Chi Minh’s thought on international solidarity in order to build the friendship, solidarity between the three countries. In the context of globalization and international integration today, strengthening the solidarity between the three nations in a spirit of friendship and cooperation pursuant to Ho Chi Minh’s thought on international solidarity has increasingly important significance. Therefore, the study and application of Ho Chi Minh’s thought on international solidarity in order to strengthen the solidarity of Cambodia with Vietnam and Laos are urgently significant issues in both practice and theory.